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以壳聚糖为生物质碳源,通过一步水热碳化法对凹凸棒石进行亲有机改性,对改性凹凸棒石进行表征,研究了其对Cr(Ⅵ)的静态和动态吸附性能,对其除Cr(Ⅵ)机制进行了初步探讨.结果表明,改性凹凸棒石表面有丰富的羟基、氨基和羧基等有机官能团,壳聚糖碳化产物成功负载于凹凸棒石表面.在实验的pH值范围内,总铬去除率随pH值增加先增大后减小,pH为1和2时总铬去除率分别为11.7%和80.8%,pH为3时总铬去除率降至10.2%.总铬吸附量随Na~+浓度增加而降低.对总铬的吸附等温线符合Langmuir模型,最大吸附量高达204.1 mg/g.改性凹凸棒石对总铬的动态吸附主要受颗粒内扩散控制,在强酸性条件下(pH=2),去除Cr(Ⅵ)是吸附-还原-再吸附的耦合过程.
Chitosan was used as biomass carbon source, and the attapulgite was modified by one-step hydrothermal carbonization method. The modified attapulgite was characterized and its static and dynamic adsorption properties to Cr (Ⅵ) Cr (¢ ö) mechanism of the modified attapulgite was studied.The results showed that the surface of the modified attapulgite was rich in organic functional groups such as hydroxyl, amino and carboxyl groups, and the carbonized product of chitosan was successfully supported on the surface of attapulgite.In the experimental In the pH range, the total chromium removal rate first increased and then decreased with the increase of pH value. The total chromium removal rates were 11.7% and 80.8% at pH 1 and 2, respectively, and decreased to 10.2% at pH 3 . The total chromium adsorption decreases with the increase of Na ~ + concentration.The adsorption isotherm of total chromium conforms to the Langmuir model and the maximum adsorption capacity reaches as high as 204.1 mg / g.The dynamic adsorption of total chromium by modified attapulgite is mainly affected by intraparticle diffusion Under the condition of strong acidity (pH = 2), removal of Cr (Ⅵ) is the coupling process of adsorption-reduction-reabsorption.